Content Module set to show 3 categories at a time sometimes shows only 1 or 2

-- HikaShop version -- : 3.2.1
-- Joomla version -- : 3.8.7
-- Browser(s) name and version -- : Safari 11.1
-- Error-message(debug-mod must be tuned on) -- : No error message

Hello:

I have a Content Module being shown on a SP Page Builder page set to show 3 categories randomly, but sometimes it only shows 1 or 2.
This happens randomly in all of the three website languages: PT, ES and EN.

Please take a look at the images attached.

I have a feeling that this behaviour has something to do with the caching system, because when I clean the cache and refresh the page I get a different output: sometimes it gets it right and shows 3 categories, other it won't.

Help is appreciated.

Thank you,
Rui Braz